Greg Bearís novel Quantico was a long time coming to the U.S. market, his publisher evidently thinking that it was too real for tender American sensibilities in the wake of events in late 2001.

Finally released in the U.S., the novel is more startling now than when it was first published in the U.K. in 2006, especially in the wake of the recent suicide of Bruce Ivins, the federal biodefense scientist who was being investigated for the 2001 anthrax mailings in the FBI case known as Amerithrax. The mailings resulted in the death of five people and the infection of 17 others.

Using Amerithrax as a jumping-off point, Bear has constructed a gripping thriller in which the anthrax mailer (based on Ivins, perhaps, but more likely on Steven Hatfill, the scientist originally indicted in the case but who was recently exonerated and given a nearly $6 million settlement) is himself a pawn in an even more nefarious plot.

The novel opens with the FBI under a political cloud, just as it was post-9/11: the Bureau is threatened with extinction for having bungled its chance to apprehend the terrorists responsible for 9/11 and other atrocities. (The Dome of the Rock, for instance, has been blown to bits.) Evidence that something even worse in the words is being ignored by top officials in the intelligence community. It looks like a new plague is set to be unleashed, and this one targets specific ethnicities - Muslims, Jews, maybe both.

Novice agent Bill Griffin goes to work with bioterror investigator Rebecca Rose. Large quantities of a weird hybrid yeast are discovered at a defunct winery in Temecula, California, and the same spores turn up at the compound of a religious fanatic in backwoods Washington State. Thing is, the yeast spores arenít lethal or even dangerous; after all, yeast is yeast, right? So the FBI agents are taken off the case and redeployed as, basically, floor moppers.

But then thereís a strange outbreak of memory loss in middle America. Rose and Griffin finagle their way back onto the case and learn that the situation isnít one of typical bioterror but something much, much more dire.

As ever, Bear spins a great, tightly plotted tale full of speculative but plausible scenarios and gadgets. Although this isnít Bearís best novel, a mediocre effort from this writer is better than the best from almost any other writer of high-tech thrillers. Bear is smart and imaginative and manages, novel after novel, to harness his talents to produce thought-provoking, spine-tingling goodness.